Feed-valve device



INVENTOR c. c. FARMl-:R

FEED VALVE DEVICE original Filed March 4, 1926V April 23, 1929.

`fcliYDE QFARMR ATTORNEY Patented Api. 23, 1929.

AUNI'ITED S'Tii'r'1i-5,5,1

CLYDE o. FARMER, on PITTSBURGH, PENnsYLvANiA, fission-on. TofrrrnWns'JING-c' HOUSE AIR BRAKE COMPANY, 'OF WIIMERDING, PENNSYLVANIA, .AVCORPORATION' l 0F PENNSYLVANIA.

" FEED-vALv DEVICE.

E voriginal application filed Mai-iii f1, 1926, Serial No. 92,180;Divided and this application 'flied Novembervalve devicesand morelparticularly to the.

. 20,1925. -seriai no. 149,669. i

rllhis invelition relates` to feed or reducing i type employed inrailway service yfor maintaining ythe fluid pressure in the brakc'pipeof the fluid pressure brake system. The present application is adivision of my application, VSerial No. 92,180, liled March 4, 1926. l

In the accompanying drawing; Fig. 1 is a Acentral sectional view/'of afeed valve'devlce embodying my improvements; Fig. 2 a section on theline 2-2 of Fig. 1; and Fig. 3 an end view of the piston stem guidingmeans.

Tliefeed valve devicemaycomprise a cas# ing 1 including a fluid pressuresupply poi'- tion and a regulating portion. kThe supply portion includesa piston 2 contained in piston chamber and a slidevalve 4, contained invalve chamber 5 and adapted to be operated by piston stem 6, which isconnectedto piston 2. c. The regulating portion comprlsesa flexiblediaphragm 7, subject on one side to thepressure of 'an adjustableregulating spring 8. The stem 9 of a regulating valve 1() engages theopposite side of the diaphragm 7 and said valve is subject to thepressure of a coil spring 11. i

According to one feature of my invention a one piece bushing 12 isprovided for receiving the piston 2 and the slide valve 4. Said bushingis machined to provide a seat for the slide valve4 and to receive thepiston 2, and

is provided with an annular flange 18 inter-y mediate the ends of thebushing, for engaging a gasket 14. .The outer end of the bushing alsoengages a gasket 15. The bushing 12 is maintained lin place by the capplate 16 and an interposed gasket VV17 The outerend of the piston stem 6is provided with a guide portion 18 which iitsa machined bore in thebushing 12 and which is provided with a plurality of spiral grooves 19.

A passage 20, which communicates with piston chamber 3, leads throughthe cap plate 16 and communicates, through a choke plug 21, With achamber 22 in the casing 1. The choke plug 21 is provided with a centralrestricted port 23 and radiating from said port 23 at a pointintermediate the ends are restrictedports 24." Chamber 22'isconnected-"- to 'the main reservoirtnot shown) through pipe 25. c i

The passage 20 is connected to valve chamber 26 containing theregulating valve 10.'

The regulatingvalve 1() is carried in abuslling 27 having aseat for thevalve and said bushing is provided with an annular flange 28 adapted toengage a gasket 29.

A. cap nut 30`lias screw-threaded 'engagement ill the casing 1 and isdisposed in alineprovided with an annular sleeve portion 31 which isadapted to engage the flange 28of the bushing 27. f 1

'ment with theV valve-10. Saidcap nut is i The bushing27 is an easy` litin the casing 1, so'that in case it sllould be desired to replace abushing, the old bushingmay befreinoved with the fingers and a new oneinstalled. Afterthe new bushing is installed,

the plug 301s applied and screweddown, the 'l sleevel serving as a gageto accurately adjust the bushing to a predeterminedv position withrespect tothe diaphragm 7.` As a consequence, thevalve 10 and its stem 9will be properly positioned with respect to the dia-y phragm.

The one-piece bushing 12 .may also be re moved when desired and a newone installed, by merel taking off the cap plate 16, the bushing eing asufficiently loose fit in the casing, to permit the bushing to be easilyremoved by the hands of the operator.

. The piston stem guide 18 is provided with the spiral grooves 19, sothat while the grooves vprovide communication between the chambers atthe opposite sides of the guide portion'and the consequent maintenanceof` balanced fluidpressures on the guideiportion, the spiral arrangementof the grooves prevents possible cutting of grooves in the bushing bythe to and fro movement of the guide portion when the feed valve'isoperating,

' and furthermore, any particles of dirt or metal will be caught `in theyspiral grooves and will thus be prevented from getting between theguide portion and its bore in the bushing, which would otherwise causepossible cutting of the guide surfaces.

The provision ofl a plurality of restricted *ports 24 in the choke plug21 is for the pur- I claim as new and desireto secure ^by LettersV Ytheflow of air.

pose of ensuring an always open passage for If one or more of the ports21 should become clogged With dirt or particles of foreignumatter,therewillstill .be an open port, `through whichL air :can lroW. At thesame time, the flow is limited to the predetermined rate as fixed by therestrictedrarea of a single port and the restricted area ofthe centralport 23. l'

Having now described my invention, what Patent, is

1. A valve device comprising a piston,

slide valve, a piston stem connected to said piston for operating saidvalve, and a guide portion carried by said stemt and ,provided Withspiral grooves.

VM2. IA fluid ,pressure valve 'device comprising a casing, a .bushinglmountedin lsaid casing, a pistonand vslide :valve mou-ntedun saidbushing, a piston stem `foroperatingv saidy valve, and a cylindricalguide fportion carried by said piston stem and working in said bushing,and having a plurality of spir-ally arranged grooves.

I 3. A fluid pressure valve device comprising a casing; a one-piece'bushingfmounted in said casing vandhavingA a piston chamber fand a thecasing in position to prevent leakage between the annular chambers ofthe casino'.

4. A iiuid pressure valve device comprising a.casinga one-piecebushingmounted in said casing and-*having afpiston v`chamber and a valvechamber, a piston in said piston chamber, a valve in said valvechamber,said casing having an annular chamber :surrounding the valve chamberportion fof-saidbushing and an annular chamber=surroundling the pis-Vton chamber portion of said bushing,` the bushing being` provided yWithopenings connecting-the valve 'chamber vvith'the annular chambersurrounding said piston chamber portion, a gasket interposed betweensaid lbushing and the casingin positionrto prevent .leakage between .the.annular chambers .of the casing, Vand al gasket interposed .bevveen.the casing and the end ofthe valve chamberporvtion of the :bushing toprevent leakage of luid 'betweenthe valve chamber `and vvthe `annularchamber surrounding the valve chamber .portion ofthe bushing. y Y

S5. A feed valve `device'comprisinga vcasing having a valve chamber anda pistonchamber, a. supply valve invsaid valve eharnber.,-a piston `insaid Vpiston chamberior operating said valve, and a plug interposed inasupplypassage in said casing, -throu-ghvvhich `fluid under `.pressureissupplied'to said piston chamber, said plug having; a. centra-lrvertical-lyv disposed restricted passage :and radial restricted passages`con-necting the-supply `passage-With 4saidcentral;passage. Y y

In testimony whereof I' have hereuntoset any hand. n y

@Liann o; FARMER,

